UD-Brookhaven Research

UD-Brookhaven Research

New areas of complementary strength and strategic importance

The U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and the University of Delaware have begun a two-year joint initiative to promote collaborative research in new areas of complementary strength and strategic importance. Though Brookhaven Lab and UD already have a tradition of collaboration, especially in catalysis, this initiative encourages partnerships in strategic areas where that tradition does not yet exist. After considering several potential areas, a committee from Brookhaven and UD selected two projects—one on rice soil chemistry and the other on quantum materials—for the new initiative. For each project, one graduate student based at Brookhaven and one graduate student from UD will work with and be supervised by a principal investigator from each respective institution. The research, to start in October 2019,  is funded separately by the two institutions. Brookhaven funding is provided through its Laboratory-Directed Research and Development program, which promotes highly innovative and exploratory research that supports the Lab’s mission and areas for growth.

The rice soil chemistry project, “The rice of the future: How growing practices can decrease human exposure to toxins,” is co-led by Ryan Tappero, lead scientist at the X-ray Fluorescence Microprobe (XFM) beamline at the National Synchrotron Light Source II (NSLS-II)—a DOE Office of Science User Facility at Brookhaven—and Angelia Seyfferth, an associate professor of biogeochemistry and plant-soil interactions in UD’s College of Agriculture and Natural Resources.

The quantum materials project, “Growth and characterization of quantized antimony-based topological insulators,” is co-led by Peter Johnson, group leader of the Electron Spectroscopy Group in Brookhaven’s Condensed Matter Physics and Materials Science Division, and Stephanie Law, the Clare Boothe Luce Assistant Professor of Materials Science in UD’s College of Engineering.

“Our existing collaborations with UD are producing exceptional results, and we hope that we can expand this success to other strategic areas of research through the joint initiative,” said Priscilla Antunez, assistant director for strategic partnerships at the Center for Functional Nanomaterials (CFN)—another DOE Office of Science User Facility at Brookhaven—and coordinator of the Brookhaven-UD relationship.

“The University of Delaware is pleased and excited to expand research collaborations with Brookhaven National Laboratory,” said Charles G. Riordan, UD vice president for research, scholarship and innovation, and professor of chemistry and biochemistry. “Our work together is destined to have positive and far-reaching impacts, of benefit to our students and to society.”

Understanding metals in rice grain

Rice is a staple food consumed throughout the world, so it is critical to ensure that rice is safe for human consumption. Most rice is grown under flooded soil conditions, which mobilize the toxic and cancer-causing element arsenic that gets absorbed by the roots of rice plants. Moreover, the amount of mobilized arsenic increases at higher temperatures, posing food safety concerns related to climate change. Though approaches to reduce soil flooding (and thus arsenic mobilization) have been proposed, they result in the uptake of a different but also toxic element: cadmium (Cd).

Seyfferth has been pioneering research on the impact of incorporating silicon —a rice nutrient—into the soil to reduce both arsenic and cadmium accumulation in the rice grain.

“Silicon is a critical nutrient for rice and protects the plant against stress,” said Seyfferth. “It also turns out that the common form of arsenic present in flooded rice paddies is chemically similar to dissolved silicon and they both are taken up by roots via the same pathway. By increasing silicon, we can limit arsenic uptake by roots. This leads to less arsenic in the rice grain and higher yield even under flooded conditions that already minimize cadmium uptake. Silicon also causes plants to grow larger, which decreases plant concentrations of toxic elements.”

Now, Seyfferth will collaborate with Tappero and NSLS-II scientific associate Randy Smith to understand how rice-growing practices and conditions influence the distribution of arsenic and cadmium, as well as the important micronutrients zinc (Zn) and iron (Fe).

At UD, the scientists will use laser ablation inductively coupled plasma mass spectrometry — an analytical chemistry technique to map elemental composition — as a screening tool to identify rice tissue samples for high-resolution imaging and spectroscopy at NSLS-II’s XFM beamline. At NSLS-II, they will perform micro-focused x-ray fluorescence imaging and x-ray absorption spectroscopy experiments. In both techniques, x-rays are directed at the sample to induce a response that is characteristic of the sample’s elemental composition (fluorescence emission) or its local chemical states and electronic structure (absorption spectra). The scientists will grow the samples under a variety of environmental conditions, including elevated silicon concentrations, flooding levels, and temperatures. These studies also will help optimize rhizosphere microcosms—imaging devices with a window into the region of soil directly near plant roots (rhizosphere)—that Tappero is developing to visualize As release and uptake by rice roots.

“Custom sample environments developed as part of this project with UD Plant and Soil Sciences will benefit other XFM users that aim to image trace elements in situ at the soil-root interface,” said Tappero.

Novel quantum materials

When materials have nanoscale (billionths of a meter) dimensions, their electrons can only occupy specific (discrete) energy levels. This phenomenon, called quantum confinement, occurs when the nanostructures—for example, wires or dots—are smaller than a critical length scale. The unique properties of such nanostructures are of interest for many applications, including quantum computers.

To date, much of the research on quantum confinement has focused on semiconductor materials, which have an electrical conductivity in between that of conductors (high conductivity) and insulators (low conductivity). But recently, scientists have been turning their attention toward a new class of materials that behave as insulators internally but conductors on the surface (i.e., electrons can only move along the surface). The surfaces of these topological insulators are special because they are protected from backscattering, which occurs when electrons hit atomic defects or other imperfections in a crystal structure or move in response to vibrations of the atoms. The scattering of electrons is problematic because it interferes with the flow of electric current, causing energy dissipation and thus loss.

Some scientists have theoretically proposed that the surfaces of topological insulators should also have electrons of discrete energy levels that are “topologically” protected. Law and Johnson will test this theory by growing self-assembled quantum dots from a topological insulator made of the elements bismuth, antimony, and telluride and measuring the dots’ energy level spectrum.

“Topological insulators are already known to be interesting materials from both a physics and an engineering perspective,” said Law. “What isn’t known is how they behave when confined to extremely small scales. The collaboration between UD and Brookhaven will allow us to address these questions directly, and in so doing, uncover new physics and discover new applications for these materials.”

At UD, Law will grow samples of varying size and chemical composition with a thin-film deposition technique called molecular beam epitaxy and characterize the structure of the samples using x-ray diffraction and microscopy techniques. Then, at Brookhaven, Johnson and team member Dario Stacchiola—group leader of the CFN Interface Science and Catalysis Group—will measure the samples’ energy spectra through scanning tunneling spectroscopy (STS) and angle-resolved photoemission spectroscopy (ARPES). In STS, a voltage is applied between a sharp metallic tip and a sample, allowing electrons to tunnel between the two. The amount of electrical current is proportional to the density of states—the number of electrons per unit volume over a given energy level. In ARPES, x-ray or ultraviolet light is directed on the sample, and the energy and momentum of the emitted electrons are measured.

“This study will allow us to understand the electronic structure of topological insulators at the nanoscale, by measuring their quantized energy level spectrum,” said Johnson. “Our research could help us answer fundamental questions about the physics of topological systems. It could also be used as the foundation to develop qubits—the counterpart to the binary bits used in today’s computers—that operate at room temperature over extended distances for more efficient computing.”

Brookhaven National Laboratory is supported by the U.S. Department of Energy’s Office of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science.

Salivary Gland Study Wins Best Poster Award at GRS

Salivary Gland Study Wins Best Poster Award at GRS

Graduate students recognized for tissue engineering research

Materials science and engineering doctoral students Eric Fowler and Anitha Ravikrishnan received the Best Poster Award at the Gordon Research Seminar on Multi-Scale Adhesion Mechanics and Signaling, held on June 23 and 24, 2018. Their poster presentation, Bioactive Peptides Direct Salivary Gland Stem/Progenitor Cell Fate in a Synthetic Matrix, described a tissue engineering strategy under development to treat xerostomia, or dry mouth.

Dry mouth is a symptom of radiation therapy for the treatment of head and neck cancers, which can irreversibly damage patients’ salivary glands. Dry mouth can make speaking, swallowing, and eating difficult. It can also promote cavities and other oral health problems. Researchers want to develop a functional, tissue-engineered salivary gland, but first they need to understand how salivary cells respond to the synthetic environments.

The research team took human salivary/stem progenitor cells from patients before those patients underwent radiation therapy. Then, they cultured the cells in a custom-designed hydrogel containing peptide fragments of extracellular matrix proteins found in the native tissue. They found that certain peptide combinations direct the differentiation of these cells toward acinar phenotype, which secrete saliva; while other peptide signals make them more like ductal cells, which direct the flow of saliva.

Fowler accepted the award at the conference.

“We have engineered a synthetic environment that gives us complete control over what biological signals we are sending the salivary cells and this control allows us to tease out the role of each biological signal,” Fowler said. “In essence, we have used materials engineering to better understand salivary gland biology, to move closer towards our goal of restoring salivary gland function.”

NSF Graduate Research Fellowships

NSF Graduate Research Fellowships

Twelve UD students, alumni win prestigious research support

A dozen University of Delaware students (undergraduate and graduate) and alumni have won National Science Foundation Graduate Research Fellowships as the prestigious competition marks its 65th year. Fourteen others received honorable mention designations.

The awards — for which more than 13,000 applicants competed this year — include three years of funding at $34,000 per year, plus $12,000 in cost-of-education allowances to the school for study leading to a master’s or doctoral degree in science and engineering. The total of these awards is almost $1.4 million — a significant boost for the students and their research.

“Research is incredibly important,” said Dianna Kitt, a senior majoring in environmental engineering and one of UD’s 12 winners. “On a large scale, research is what drives our society and allows us to create new technologies and processes that protect humans, animals and the environment. On a smaller scale, research pushes you as an individual to think outside of the book and answer problems that no one else has answered before.”

The awards make a powerful statement about these students, said Donald Watson, associate professor of chemistry and biochemistry and the department’s associate chair for graduate studies. That department had four winners – two undergraduates and two graduate students – including doctoral student Sarah Krause in Watson’s research group.

“This includes all fields of science and engineering and these awards go to extraordinarily high-quality students,” he said. “It recognizes their ability and frees students to do science. And getting multiple awards in a single year is a mark of quality for our program.”

Nationally, there were 2,000 winners (about 15 percent of all applicants), representing 449 different schools, all 50 states, the District of Columbia and other U.S. territories. Winners included 1,158 women, 498 individuals from underrepresented minority groups and 726 undergraduate seniors.

“This is one of the most prestigious awards a student can get,” said Julie Maresca, assistant professor of civil and environmental engineering and Kitt’s faculty mentor. “These awards are highly competitive and truly a recognition of the students’ potential for future success.

“The students who get these fellowships have demonstrated not only that they are among our top students, but also that they can convincingly propose a multiyear research project and are committed to broadening participation in their fields.”

UD’s NSF Graduate Research Fellows:

* Ian Berke of Albany, New York, who earned his bachelor’s in biomedical engineering in 2016 and now is pursuing a doctoral degree in biomedical engineering at Washington University in St. Louis, Missouri.

“In my sophomore year at UD, I had a sports-related knee injury that required surgery (ACL tear). This got me interested in orthopedic research and I was paired with Christopher Price, assistant professor in biomedical engineering, for a summer scholar research opportunity, in imaging. During the summer and in the following year or so we imaged bone and cartilage using refractive index matching techniques. Dr. Price really sparked my interest in the field and showed me the many avenues researchers were taking to combat osteoarthritis.”

* Hannah Clipp of Bel Air, Maryland, who earned two bachelor’s degrees — in wildlife and fisheries resources and multidisciplinary studies — at West Virginia University and is pursuing a master’s degree in wildlife ecology at UD.

The focus of her research is bird migration and stopover ecology and bird conservation.

* Jonathan Galarraga of Belcamp, Maryland, a Unidel Eugene du Pont Scholar who earned an honors bachelor’s degree in chemical engineering in 2016 and will pursue his doctorate at the University of Pennsylvania, where he will study tissue engineering, biomaterials, 3D-printing and cartilage repair.

“Biomaterials are changing possibilities for medicine and healthcare across the world because they provide new avenues for exploring prospective therapeutics, modeling disease pathology and assessing drug toxicity. In my Ph.D. thesis, I will develop new materials approaches for tissue repair through rational material design and impact society through new product development. As a Ph.D. student in Dr. Jason Burdick’s Polymeric Biomaterials Lab at the University of Pennsylvania, I am eager to establish strong relationships with leading experts in the country so that I may design and deliver clinically viable biomaterials.”

At UD, Galarraga worked in the research group of Christopher Kloxin, assistant professor of chemical and biomolecular engineering.

“Throughout my time in the CJK lab, I gained a strong appreciation for collaborations in research, developed intimate knowledge of the materials science research landscape, and enjoyed the privilege of learning from many great mentors.

“The aims of my career are to conduct research on biomaterials and bring clinically viable biotechnology to market while teaching as a university professor. In doing so, I will improve the quality of life for people with disabilities and diseases, increase the U.S.’ competitiveness in the growing biomedical device industry and improve the prospects for future biomedical research. In addition to commercially developing these technologies, I will employ my bioengineering expertise to help develop and implement policies that will ensure that future biomaterials are readily accessible and disseminated to underserved patient populations.”

* Nicholas Geneva of Owings, Maryland, an honors degree candidate who is completing his bachelor’s degree in mechanical engineering and will pursue a doctoral degree, continuing his work integrating state-of-the-art computer technology and engineering at UD.

“Working with Dr. Lian-Ping Wang [professor of mechanical engineering] and his graduate students is largely the reason why I decided to pursue a Ph.D. His work has shown me that the integration of state-of-the-art computer hardware and engineering is a very important challenge that is facing the scientific community today. Computing, whether through traditional CPUs or other hardware accelerators, is becoming ever more powerful, but exploiting this power effectively to solve the difficult engineering problem is by no means trivial.”

* Rebekah Houser of Newark, Delaware, who earned a bachelor’s degree in electrical engineering and will continue research on vehicle-to-grid technology and firmware for an infrared scene projector.

“Electric vehicles equipped with vehicle-to-grid technology can provide valuable services to electric power generation and distribution systems. These services promote adoption of electric vehicles and facilitate increased incorporation of renewable resources into the electric power grid. Infrared scene projectors enable more efficient testing of infrared imaging systems that serve as critical tools for first responders, law enforcement and military personnel.”

* Dianna Kitt of Aberdeen, Maryland, a Unidel Eugene du Pont Scholar who is completing her bachelor’s honors degree with distinction in environmental engineering and will pursue graduate-level research in water treatment.

“I grew up near the Chesapeake Bay so I have always been passionate about clean water and the environment. When I was in high school, I was inspired by my AP biology teacher (who was actually a retired research scientist) to work in a research lab for the first time and I fell in love with research. I knew that I wanted to pursue my passion for improving the environment as my career, and I knew that a career in environmental engineering research would allow me to not only study the environment but also develop techniques and processes to protect it.”

* Jodi Kraus of Monument, Colorado, who earned her bachelor’s degree at Drexel University and is a second-year grad student in chemistry and biochemistry at UD.

In the laboratory of Tatyana Polenova, professor of chemistry and biochemistry, she has focused on determining the atomic-level structure and dynamics of actin-associated protein assemblies using the technique Magic Angle Spinning NMR.

“I was drawn to using solid-state NMR spectroscopy to study large protein assemblies because the scientific understanding of fundamental biological processes is rapidly expanding, and it is of utmost importance to continue developing new methodologies to study these complex systems. I believe that in order to fully understand these biological processes and identify new potential drug targets (in the case of disease), we must investigate their most basic properties. Additionally, I am interested in methods development and instrumentation because I personally find it gratifying to track the exact physical dynamics which correlate to larger functional roles within proteins.”

* Sarah Krause of Harford County, Maryland, who earned her bachelor’s degree in chemistry at Towson University and is pursuing her doctorate in organic chemistry at UD in Donald Watson’s research group.

The focus of her research is chemical synthesis and catalysis.

* Andrew Kuznicki of Boston, Massachusetts, who is majoring in chemistry.

His research has been in the inorganic chemistry lab of Joel Rosenthal, associate professor of chemistry and biochemistry.

* Peter Sariano of Collegeville, Pennsylvania, an honors degree candidate who is majoring in biomedical engineering and plans to pursue research in tissue engineering.

“Biomedical research is the foundation for medical discovery. Research drives our understanding of disease and allows us to develop treatments to address unmet clinical needs.”

* Hannah Wastyk of Palmyra, Pennsylvania, a Unidel Eugene du Pont Scholar and honors degree candidate majoring in biochemistry with a minor in biochemical engineering.

“What excites me most about research on human disease is that the body is a system more perfect than any we could possibly engineer. Our immune system is the most complex line of defense we possess, and treating diseases through regulation of its already existing cellular processes to control aberrant signaling is a technique that holds almost unlimited possibilities.

“The concept of growth has always been a passion I continually strive for. Research, both in practice and in mindset, perfectly embodies this endless cycle of growth through the creation of knowledge starting with basic research and applying it to solve real-world problems through engineering.”

* Kathryn Wheeler of Boone, North Carolina, a Unidel Eugene du Pont Scholar and honors degree candidate who is earning her bachelor’s degree in environmental science and will pursue a doctoral degree at Boston University’s Department of Earth and the Environment.

I am interested in how climate change is altering forest phenology (seasonality) and how the timing of the seasons affects the forest ecosystem and global ecosystems. Specifically, at Boston University I will be working on a project that uses ecosystem forecasting to identify the holes in our understanding of phenology and seasonal variation in carbon and energy transfers between the biosphere and atmosphere. With warmer global temperatures, the growing season is expected to be lengthened in many ecosystems. A longer growing season has the possibility of increasing the amount of carbon dioxide that trees take away from the atmosphere, which consequently would likely alleviate global climate change. In order to improve the accuracy of climate change predictions, it is necessary for us to better understand forest phenology and how it affects and is affected by climate change.

Research with Delphis Levia, professor of ecohydrology and chair of UD’s Department of Geography, and doctoral student Janice Hudson introduced her to phenology.

“I became fascinated by the idea that something as seemingly simple as changing the timing of the seasons can have profound impacts on ecosystems. I became particularly interested in how phenology can then affect climate change through an ecosystems ecology course I took with Dr. Rodrigo Vargas [assistant professor of plant and soil sciences] this fall.”

Honorable Mention:

Hunter Bachman, mechanical engineering, an honors degree candidate, now at Duke University

Rabae Bounoua, psychology

Christopher Bresette, engineering, an honors degree candidate

Kamil Charubin, chemical engineering

Patrick Cronin, electrical and computer engineering

Nathan Hamilton, chemical engineering, an honors degree candidate

Alyssa Hull, chemistry and art conservation, a double honors degree recipient, now at Duke University

Joshua Lansford, chemical engineering

Charles McCutcheon, chemical engineering, now at the University of Minnesota

Bonnie McDevitt, environmental engineering, an honors degree recipient, now at Penn State University

Alexander Mitkas, chemical engineering

Samuel Modlin, neuroscience, now at San Diego State University Foundation

Lacey Perdue, bioengineering, an honors degree candidate

Jacob Wilmot, biology and neuroscience, an honors degree recipient, now at the University of California-Davis

A complete list of those offered the fellowship for 2017 is available on FastLane. For general information about the program, visit NSF’s GRFP website.